The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the claimed subject matter.
Moveable platform systems suspended by cables are known. In one embodiment, an upper platform mounted to, for example, a bridge supports a lower platform using six wire ropes. Both the upper platform and the lower platform each have three spaced apart locations where two wire ropes are joined or come together such that the wire ropes at each location come from two different locations on the other platform. A stable lower platform is obtained because the wire ropes are kinematically constrained and where the stiffness of the platform is determined, at least in part, by the tensile elasticity of the wire ropes. The lower platform can be moved in a work envelope as determined by the length of each of the wire ropes suspending the lower platform from the upper platform as well as the linear position of the upper platform on the bridge, if the upper platform is moveable on the bridge in one degree of linear motion, and/or the bridge is movable on gantry rails in another degree of linear motion.